phy: qcom-qmp-pcie: support separate tables for EP mode

The PCIe QMP PHY requires different programming sequences when being
used for the RC (Root Complex) or for the EP (End Point) modes. Allow
selecting the submode and thus selecting a set of PHY programming
tables.

Since the RC and EP modes share common some common init sequence, the
common sequence is kept in the main table and the sequence differences
are pushed to the extra tables.
Reviewed-by: Johan Hovold <johan+linaro@kernel.org>
Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
Link: https://lore.kernel.org/r/20220927092207.161501-3-dmitry.baryshkov@linaro.orgSigned-off-by: Vinod Koul <vkoul@kernel.org>

drivers/phy/qualcomm/phy-qcom-qmp-pcie.c

@@ -14,6 +14,7 @@
 #include <linux/of.h>
 #include <linux/of_device.h>
 #include <linux/of_address.h>
+#include <linux/phy/pcie.h>
 #include <linux/phy/phy.h>
 #include <linux/platform_device.h>
 #include <linux/regulator/consumer.h>
@@ -1320,10 +1321,14 @@ struct qmp_phy_cfg {
 	/* Main init sequence for PHY blocks - serdes, tx, rx, pcs */
 	const struct qmp_phy_cfg_tables tables;
 	/*
-	 * Additional init sequence for PHY blocks, providing additional
-	 * register programming. Unless required it can be left omitted.
+	 * Additional init sequences for PHY blocks, providing additional
+	 * register programming. They are used for providing separate sequences
+	 * for the Root Complex and End Point use cases.
+	 *
+	 * If EP mode is not supported, both tables can be left unset.
 	 */
 	const struct qmp_phy_cfg_tables *tables_rc;
+	const struct qmp_phy_cfg_tables *tables_ep;
 
 	/* clock ids to be requested */
 	const char * const *clk_list;
@@ -1367,6 +1372,7 @@ struct qmp_phy_cfg {
  * @pcs_misc: iomapped memory space for lane's pcs_misc
  * @pipe_clk: pipe clock
  * @qmp: QMP phy to which this lane belongs
+ * @mode: currently selected PHY mode
  */
 struct qmp_phy {
 	struct phy *phy;
@@ -1380,6 +1386,7 @@ struct qmp_phy {
 	void __iomem *pcs_misc;
 	struct clk *pipe_clk;
 	struct qcom_qmp *qmp;
+	int mode;
 };
 
 /**
@@ -1991,13 +1998,19 @@ static int qmp_pcie_power_on(struct phy *phy)
 	struct qmp_phy *qphy = phy_get_drvdata(phy);
 	struct qcom_qmp *qmp = qphy->qmp;
 	const struct qmp_phy_cfg *cfg = qphy->cfg;
+	const struct qmp_phy_cfg_tables *mode_tables;
 	void __iomem *pcs = qphy->pcs;
 	void __iomem *status;
 	unsigned int mask, val, ready;
 	int ret;
 
+	if (qphy->mode == PHY_MODE_PCIE_RC)
+		mode_tables = cfg->tables_rc;
+	else
+		mode_tables = cfg->tables_ep;
+
 	qmp_pcie_serdes_init(qphy, &cfg->tables);
-	qmp_pcie_serdes_init(qphy, cfg->tables_rc);
+	qmp_pcie_serdes_init(qphy, mode_tables);
 
 	ret = clk_prepare_enable(qphy->pipe_clk);
 	if (ret) {
@@ -2007,10 +2020,10 @@ static int qmp_pcie_power_on(struct phy *phy)
 
 	/* Tx, Rx, and PCS configurations */
 	qmp_pcie_lanes_init(qphy, &cfg->tables);
-	qmp_pcie_lanes_init(qphy, cfg->tables_rc);
+	qmp_pcie_lanes_init(qphy, mode_tables);
 
 	qmp_pcie_pcs_init(qphy, &cfg->tables);
-	qmp_pcie_pcs_init(qphy, cfg->tables_rc);
+	qmp_pcie_pcs_init(qphy, mode_tables);
 
 	/*
 	 * Pull out PHY from POWER DOWN state.
@@ -2097,6 +2110,23 @@ static int qmp_pcie_disable(struct phy *phy)
 	return qmp_pcie_exit(phy);
 }
 
+static int qmp_pcie_set_mode(struct phy *phy, enum phy_mode mode, int submode)
+{
+	struct qmp_phy *qphy = phy_get_drvdata(phy);
+
+	switch (submode) {
+	case PHY_MODE_PCIE_RC:
+	case PHY_MODE_PCIE_EP:
+		qphy->mode = submode;
+		break;
+	default:
+		dev_err(&phy->dev, "Unsupported submode %d\n", submode);
+		return -EINVAL;
+	}
+
+	return 0;
+}
+
 static int qmp_pcie_vreg_init(struct device *dev, const struct qmp_phy_cfg *cfg)
 {
 	struct qcom_qmp *qmp = dev_get_drvdata(dev);
@@ -2220,6 +2250,7 @@ static int phy_pipe_clk_register(struct qcom_qmp *qmp, struct device_node *np)
 static const struct phy_ops qmp_pcie_ops = {
 	.power_on	= qmp_pcie_enable,
 	.power_off	= qmp_pcie_disable,
+	.set_mode	= qmp_pcie_set_mode,
 	.owner		= THIS_MODULE,
 };
 
@@ -2235,6 +2266,8 @@ static int qmp_pcie_create(struct device *dev, struct device_node *np, int id,
 	if (!qphy)
 		return -ENOMEM;
 
+	qphy->mode = PHY_MODE_PCIE_RC;
+
 	qphy->cfg = cfg;
 	qphy->serdes = serdes;
 	/*
@@ -2278,7 +2311,8 @@ static int qmp_pcie_create(struct device *dev, struct device_node *np, int id,
 
 	if (IS_ERR(qphy->pcs_misc)) {
 		if (cfg->tables.pcs_misc ||
-		    (cfg->tables_rc && cfg->tables_rc->pcs_misc))
+		    (cfg->tables_rc && cfg->tables_rc->pcs_misc) ||
+		    (cfg->tables_ep && cfg->tables_ep->pcs_misc))
 			return PTR_ERR(qphy->pcs_misc);
 	}